Megan Knapp

Unearthing history

3/7/2019

Studying fossils to learn about the past and present

Jessica Hill / Asst. Managing Editor
George Shillcock / For The Post

Fossils may seem like a faraway concept, hidden under layers of rocks in the west or behind a glass display case in a museum, but paleontology and fossil sites are much closer to home.

Alycia Stigall, an Ohio University geological sciences professor, works on the Cincinnatian project, which studies environmental changes related to invasive species particularly in the Cincinnati area.

The Cincinnatian Series, or just the Cincinnatian, is a region around Cincinnati that has many preserved and diverse fossils. Part of the Upper Ordovician, which is named after the second period of the Paleozoic Era, the Cincinnatian is made up of 450-million-year-old deposits of ancient ocean marine life.

The region is very well known among many paleontologists; even Charles Darwin was aware of its significance towards studying evolution, Stigall said.

“The rocks around Cincinnati, Ohio, are some of the most diverse and spectacularly preserved fossils from this time period (ordovician) in the world,” Stigall said. “We are just so lucky to be only a couple hours drive from these rocks.”

Stigall works with shallow or marine invertebrates or shelly animals.

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Nate Swanson | FOR THE POST

Professor Alycia Stigall poses in her fossil lab in Clippinger Laboratories on March 4, 2019.

She primarily looks at how new species form, evolve and eventually go extinct and what happens with the species’ geographic range and habitat preferences. She also studies how the ecosystems and other species have evolved and reacted when an invading species infiltrates an environment.

“Understanding long-term impacts of invasive species is very hard to do with modern animals because you can study the zebra mussels over decades, but after that you run out the career path of an individual person,” Stigall said. “And so if you want to know what happens of thousands or tens of thousands of years, you can look at similar events in the fossil record.”

Specifically, Stigall studies brachiopods, a shelly animal that look somewhat like clams but made from completely different minerals, she said. With brachiopods, there are many different species, and paleontologists are able to recognize those. Different species of brachiopods can end up changing the ecosystem.

In Cincinnati, Stigall said, there is a big influx in the rocks that show there was a new invasion of species that caused an extinction. Stigall has learned that not all invasions are the same — some result in a couple species going extinct, whereas large-scale invasions can contribute to mass extinctions.

Stigall brings about two dozen students to the region participate in the project of studying fossils in the Cincinnatian.

Ian Forsythe, a senior studying geological science, wasn’t aware of how rich the Cincinnati area is in terms of fossils before he came to OU, but now he finds himself following in Stigall’s footsteps since joining her project. He hopes to become a paleontologist and study invertebrates after college, and he is currently working on brachiopods as well.

“They’re very common. They fossilize pretty well and there is a good sample size,” Forsythe said. “That's probably where my interests are going to lie in the future as well.”

He has been working with a genus of brachiopods called rafinesquina, which are invertebrates and are distantly related to mollusks. Rafinesquina have a bivalve shell and resemble clams.

Stigall and her students who are a part of the project dig up fossils and perform morphometrics in which they measure the characteristics to learn more about the rafinesquina and the different types that once existed. No one has ever studied much about them before, Forsythe said.

Identifying the different species is the first step to analyzing other facets of the animals, Forsythe said, such as how they lived, moved and then died.

“Not many new species have been discovered recently, but they are making strides everyday to figure out how we can relate these past species and their lives to current events,” Forsythe said.

Stigall and her students hope to expand their studies to other places around the world and recognize the similarities between the Cincinnatian and other geographic regions.

“I really do think that the patterns in cincinnati are generalizable to the whole world,” Stigall said.

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Development by: Midge Mazur / For The Post

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